Epoxy caulk?

[Biofish]

Trying to fill a few vertical gaps on the frames and chines. I can't just pour epoxy into the gap becuase it would just flow out of the sides. I have tried taping the sides of the area i want to epoxy and then filling the hole and then taking the tape away after it has cured. This has lead to a big mess and i really don't want to try it again. NOt to mention the waste of glue.

My idea is to somehow load a chalk gun or even a bakery dispenser with epoxy and let it semi-cure to a less runny texture and then fill the areas that way. It is easier to control a bead of epoxy than a cup of the same.

Any suggestions or disapprovals?

Can i even buy a empty calking tube? Never seen one before.

Rob

[Steve Lansdowne]

You can thicken epoxy using silica thickener, and in fact this is the way to go when using it as an adhesive. I'm not sure, however, whether this is what you want to do in this particular application. You should consult a manual such as the System 3 epoxy book or one of the West System publications for particulars.

[JimD]

Rob, like Steve says, thickened epoxy is probably what you need. Silica thickened epoxy bonds very well, is very strong, but not too easy to sand. Microbubbles (microspheres) sand easier but are not very strong and are usually used for fairing (filling gaps where tonnes of strength aren't necessary). Both will sag and run a bit down hill while curing, so I usually stuff it in the cracks and joints, and check it from time to time as it cures, stuffing it back in place if necessary.
-Jim

[Biofish]

Well, the thickening is not a problem... Silica will be added or i will just let it sit for a few minutes. The real problem is getting it into the gaps.

Maybe i need to explain myself a little more. I have a gap that is 1/4 inch wide at the top... but is 2-3 inches wide inside at the bottom. If i can i would like to use a "nozzle" to inject the epoxy into the gap and fill the hole. I can get the epoxy in without the use of a nozzle if the epoxy is thin...but then it pours out the side or bottom where i can't reach. If i thicken the epoxy then i cannot get it into the top without creating a huge mess.

my problem is how to use a nozzle to do this.. my first impression is a caulking gun,.. but i don't know if they sell empty caulking tubes... I am wondering if anyone had suggestions as to how to sqeeze this stuff in. Empty emer's glue bottle? Old baby bottle? I am just thinking off the top of my head here.

Gosh this is hard to explain.

Rob

[jeff pierce]

Originally posted by Biofish:
Well, the thickening is not a problem... Silica will be added or i will just let it sit for a few minutes. The real problem is getting it into the gaps.

Maybe i need to explain myself a little more. I have a gap that is 1/4 inch wide at the top... but is 2-3 inches wide inside at the bottom. First, thickening the epoxy is the right approach rather than trying to apply it after its started to kick. If you get it real thick, it can be forced into a gap with a putty knife rather than poured

Second, WEST system (and probably others) make syringes with tapered nozzles for injecting epoxy. Snip the nozzles so that the hole is fairly large. They can be used with thickened stuff, but it does get harder to push out, the more you thicken.

Lastly, I must admit you have managed to confuse me. I don't see where in your design gaps as you describe should exist. Can you clarify? Digital pix, maybe?

-Jeff

[ 05-17-2002, 12:47 AM: Message edited by: jeff pierce ]

[JimD]

Ok, how about... Ever write 'Happy Birthday' on a cake? No kidding, squeezing the epoxy mixture out of a makeshift sock (I think that's what those squeezy things are called) that you can squeeze and twist from the top end might work

[ford]

I have has similar problems, what worked for me was to use a pre-mixed epoxy glue and a syringe, the consistency of the glue was just right and was easy enough to load. I used the type of syringe that the plunger can be removed, this made it easier to push the glue in to fill the chamber.
Oh yes, the epoxy was warmed in the sun and of course the syringe did not have a needle in it tho' you could use a piece of plastic tube. smile.gif

[PugetSound]

Bio, if all you are trying to do is to fill a few lousy cracks then most definitely do NOT start messing around with trying to push semi-cured epoxy thru cake decorators ect. For one thing, it smacks of someone trying to re-invent the wheel. For another, epoxy is exothermic when curing so the larger the mass of epoxy the more heat is concentrated in one volume and the faster the stuff will cure!!!!!! It's likely that you would have a plastic facsimile of your wife's cake decorator.... :rolleyes:

As for the silica and micro balloons ect. It's all good stuff but you'll need to be careful that you don't inhale the stuff, also it isn't cheap.

A much much much easier and far more satisfactory solution for filling cracks is to use some of that sanding dust you have been saving, preferably from the very same wood you're trying to repair. Just mix it up with some of your favorite epoxy until you have the right consistency and the rest is history. Works like a charm and is even about the same color as the surrounding wood (mabey a little darker).

[Concordia..41]

I don't get what you're trying to do either, but they do make syringes (we've got some about 3" long) for getting epoxy into small areas. BTW - it's easier to fill them by sticking the "needle" end into the thickened epoxy and withdrawing the plunger vs scooping the stuff into the end.

You can also buy empty caulking tubes. You'll need them if you ever use a two-part caulk for deck seams - should you ever be so lucky/unlucky.

[Todd Bradshaw]

Gougeon Brothers sells empty 10 oz. calking tubes to use with WEST epoxy (part #810 - two for about $3.50). That said, a 3" gap is a pretty big hole to try to fill with a resin mixture. Their graphite powder would be another substance that could be used for thickening. Resin mixed with a fairly high percentage of graphite seems to make a somewhat lighter and quite tough chunk of plastic.

[Tuomas Raivio]

Bio, I fixed some freeze cracks in a wooden part of a keel made oh mahogany by drilling holes of suitable diameter and squeezing West System epoxy in with a large (100cc) and cheap (5 euros) catheter syringe bought from the local pharmacy. I'm sure that also silica thickened epoxy, at least in the "mayonnaise" form, as they call it in the West System literature, would flow out of the syringe. The inner diameter of the nozzle was 4-5 mm, and the syringe would have felt robust enough for some pressing by force. Even large injection syringes seem to have a too small nozzle diameter.

And just crossed my mind, I did squeeze some "ketchup" thickened epoxy with the syringe. It is possible to fill the syringe by removing the piston, which is far easier than trying suck the stuff in.

Rgds, Tuomas

[imported_Daniel]

Im not sure if I quite understand the area you are trying to fill, but how about making up some epoxy putty, using it to seal the areas where the epoxy is running out, then drilling a bigger hole to expand the existing crack, making it easier to pour/inject the epoxy in. Then if needed, just sand or heat the beads of putty used to stop the stuff from running out off.

[Doug Scherbarth]

Thicken with silica. Place in a large ziploc bag. Squeeze out excess air. Zip it closed. Cut off a small amount of corner. Better than a caulking gun; cheaper and easier to handle. Best not to use more than 5 oz at a time since it can get hot very quickly.

Good luck!

[Scott Rosen]

I'm not sure what you mean by "gaps." I think of gaps as different from cracks in the wood. If by gap you mean a bad fitting joint, then man 'o man, a three inch wide gap is a major problem. I'm only a third-rate wood butcher, but if I had a three inch gap, I'd take it apart, remeasure, and start over again.

On the other hand, if you have a very narrow gap, say 1/8" or less, that's three inches long, then I could see trying to fill it with something. I would probably want to glue in a thin filler piece of wood rather than use straight epoxy.

[Stan Derelian]

To throw in my 2 cents, I would agree with Scott. For a gap of that size, I would glue in a piece of wood.

For filling smaller gaps I have successfully used larger syringes (50 cc's or more). Take the plunger out and fill with thickened epoxy --It might need a little help filling by using a spatula-- Put in the plunger, and tap it with the plunger end down to settle the goop. Then push the air out, and fill the crevice or hole from the inside out. To keep it from sagging I tape a piece of wax paper over the filled space.

Also, for empty caulking tubes mentioned by Todd, they can be bought a lot cheaper (about 50 cents each) from Smith and Co. of CPES fame. http://www.smithandcompany.org/

[RGM]

I'm having a little difficulty visualizing what you are trying to do. I keep coming up with the same picture. You are trying to do something with epoxy that should be done with wood. Scott is on the right track. Fab and glue into place some wood pieces that tightly fill the "gaps". If need be, open them up a little to help facilitate the job. Good luck. Have you ever tried to drill and drive a fastener into a big wad of epoxy that has been located in a crucial place, such as a chine timber? It's a bad deal.

[Biofish]

Thanks Guys..

I cannot begin to describe the exact problem, but basicly Scott hit it as close as i can ever convey. Yes scott the gaps are not 3 inches wide, but long. The actual width is 1/8 to a 1/4, (i guess i did not do such a great description job) ...Although i was able to stick some wood into the gap i am going to have to fill it mostly with epoxy. It is not a structual joint that is a major part of the frame, and will bear no serious stress at all,.... it is just a boo boo that good ole Biofish screwed up on and wants to erase from existance. I need to fill it also becuase as most of you know everything moves and twists in construction, and i don't want too much going on in this area.

Thanks for the tips about the calk tubes... i am going to purchase them soon. Is it feasable to use these tubes with epoxy when "filleting" the inside of the hull to the frames after i turn the boat over?.. Wouldn't it be easier that way?.

Rob

[steve sparhawk]

Thanks to Doug for the Ziplock bag idea that I had heard before but the brain didn't eject at the right moment. Sounds like it is the way to put in fillets also since paddles and other methods always take too much fiddling. And I always tool the joint anyway.

Enough silica and the stuff stays like petroleum jelly. Slickerheck too. Not at all like trying to squeeze liquid nails out of a snoffle.For a base coat I have very successfully used sawdust from my table saw as a filler. Then second coat it with finer filler. (I won't mention Bondo.) Big spaces aren';t easy to fill perfectly in one application anyway unless one puts a smooth membrane over the patch until cured.

[JimD]

Heck, Rob, if the gaps are only an eighth to a quarter inch wide and 3 inches long I wouldn't even bother with syringes, zip lock bags or the like. I've filled dozens of gaps that big just by thickening the epoxy, slapping on a pair of latex gloves, and working it into the cracks by hand - jimd

[PugetSound]

Do like JimD advises and do it by hand (with the gloves). Your results will be better and the cleanup is non-existant. For filleting, unless you have one hell of a lot of filleting to do, just use a popsicle stick in addition to your fingers.

If the job is large and you are using your fingers, then be safe and put on and extra pair of gloves. That way if you rip one of the latex gloves you are still protected.